1. Field of the Invention
The invention is directed to a process for producing implants and components by direct shaping.
2. Description of Related Art
Dental implants in current use mostly have a geometrically defined shape. They are formed of one or more parts. In implants formed of multiple parts, the components connected to the implants likewise have a geometrically defined shape or also partially have a free-form geometry. Frameworks on implant superstructures or components can also partially have a geometrically defined shape or an entirely free-form geometry. The fabrication of implants and components is carried out by computer-aided production methods. An implant comprising multiple parts usually has a complex outer surface which is entirely or partially microstructured for contact with the bone and with the peri-implant soft tissue and has an inner surface which ensures the mechanical connection to the components.
Since one-piece dental implants have the basic disadvantage that they do not allow for the possibility of correcting the fit of a framework once they have been inserted in the jaw, metal dental implants with a superstructure formed of multiple parts (implant and screwed-in or plugged-in components) are predominantly used. The materials chiefly described are titanium or titanium alloys. Ceramic implants of aluminum oxide ceramic or zirconium dioxide ceramic also have been, and continue to be, used. In clinical respects, aluminum oxide ceramic has not proven successful either for dental implants or components. In contrast, the long-term results for frameworks on teeth fabricated from aluminum oxide have been positive. Zirconium dioxide implants are used as one-piece implants (implant and component inseparably connected in one part). Ceramic components, so-called abutments, are fabricated from zirconium dioxide ceramic. The connecting members can be made of metal or ceramic.
Ceramic implants are fabricated by abrasive methods (grinding from zirconium dioxide ceramic). Mechanical machining of ceramics is disadvantageous in that the strength of the ceramic is considerably reduced, even when dense-sintered and HIPped (HIP: Hot Isostatic Pressing) ceramic was used. Alternatively, production by means of injection molding has been described.
The production of implants by means of injection molding causes microstructures with a high proportion of residual pores which negatively influence the mechanical and biological properties of the implants.
To improve the contact between the outer implant geometry of the metal implants and the jawbone, the metal implants are additively coated or abrasively structured. The aim is to achieve a microstructure which ensures optimal contact between the bone and the implant. Additive coatings are made of inorganic substances, e.g., hydroxylapatite or bio-glasses, or of organic substances, e.g., bioactive substances, e.g., growth factors or polylactides. Abrasive structuring methods include blasting with aluminum oxide particles or etching with acids or caustic solutions, and possibly also combinations of these two methods.
For the treatment of patients with implant-supported dental restorations, the optimal implant position in the jaw and the position of the components and framework can be determined based on data of imaging data acquisition systems (computer tomography, digital volume tomography) and/or optical/mechanical digitizing methods. The production of components and frameworks can be carried out based on the data of imaging data acquisition systems (e.g., computer tomography, digital volume tomography) and/or optical/mechanical digitizing methods. Computer-aided methods have mostly been dismissed for routine clinical use. Implants in current use chiefly have standardized geometries.